Last time I went through BRS I saw a shop employee pulling a pallet of bottled water bottles. It was cling rapped in plastic through which you could see shipping labels. What are the chances that liquid was checked?
Same trip the guy ahead of me at security had a 12" wrench taken from him. Oh, sir, you could hit somebody over the head with that. I recalled that comment as I walked through the DF shop and observed hundreds of similar weapons. Made of heavy glass, many of which had a perfect handle for doing the nasty. Canes of elderly passengers seem to be OK, but woe betide you if you've got a pool cue.
It's theatre, and not very good theatre at that. To be honest it doesn't make me feel secure and the holes obvious to me certainly must be obvious to the black hats.